Automotive brake device



' 1 p 1,619,239 March 1 9.7 c. P. CASS ET AL V AUTOMOTIVE BRAKE DEVICE Filed May 25, 1923 2 Sheets-Sheet 1 INVENTORS. CHRISTOPHER P- CASS JOHN F CRAIG ATTORNEY 1 1927. 1.619339 March c. P. CASS ET AL I AUTOMOTIVE BRAKE DEVICE Fi1e d May 25, 1925 2 Sheets-Sheet 2 INVENTORS CHRISTO PH ER P. CASS \JOHN F. CRAIG ATTORNEY Patented Mar. 1, 1927.

UNITED STATES 1,619,239 PATENT. OFFICE.

onms'rornnn 1'. case, or BERKELEY, oamonnra, AND JOHN F. onus, on anon- WOOD, PENNSYLVANIA, ASSIGNORS TO TEE WESTINGHOUSE AIR BRAKE colt PANY, OF 'WEHEBDING, PENNSYLVANIA, CORPORATION OF PENNSYLVANIA.

AUTOMOTIVE Em DEVICE.

Application filed. Mas! 25,

friction face, brake shoes adapted to engage said face, a cam interposed between adjacent ends of said brake shoes, and means for operating said cam to expand the brake shoes into frictional engagement with the drum.

With a brake construction of the above character,.the expansive movement is cfit'ected at the cam ends of the brake shoes, while the anchored ends of the brake shoes have no expansive movement. This results in uneven wear of the brake shoes, the wear being greatest at the portions of the brake shoes nearest the cam.

The principal object of our invention is to provide a brake shoe and drum construction in which the brake shoes are simultaneously expanded ina plying the brakes, both at the usual cam en and at the pivot oranchor ends of the shoes, so that the wear of the brake shoes is evenly distributed throughout the extent of the wearing faces of the brake shoes.

In the accompanying drawings; Fig. 1 is an elevational view of a portion of the rear end of a motor vehicle, showing a brake construction, partly in section, applied thereto I and constructed in accordance with our invention; Fig. 2 a'plan view of the construc tion shown in Fig. 1; and Fig. 3 a section on the line 3-3 of Fig. 1.

As shown in the drawings, the reference numeral 1 indicates the rear axle housing of a motor vehicle and 2 a brake drum asso-' ciated with the rear wheel of the vehicle in the usual manner. Mounted within the brake "drum 2 are oppositely disposed brakevention, an additional cam 11, similar to the cam 8, is interposed between said ends. The

192:. Serial K0. 641,403.

cam 11 is mounted on and secured-to an operating shaft 12.

The outer ends of the shafts 9 and 12 are supported in bearings provided in a bracket 13 which is secured to the axle housing 1, and a bracket member 13 is provided with hearin for the inner ends of the shafts 9 and 12. Secured to the shaft 12 is a lever arm 15 and mounted to rotate on the shaft 9'is a lever arm 16, the arms 15 and 16 being pivotally connected at their upper ends by a link 17.

Secured to the axle housing 1 is a diaphragm brake chamber 18 containing a flexible diaphragm 19 which is operatively connected to a diaphragm rod 20. The outer end of the rod 20 is pivotally connected to the middle portion of an equalizing bar 21, one end of'which is pivotally connected to the lever arm 16 and the other end of which is pivotally connected to a lever arm 22 secured tothe extended end of the shaft 9.

In operation, when fluid under pressure is the shaft 12 through the movement of the e lever arm 16., the link 17 and the lever arm 15. The rotation of the shafts 9 and 12 op crates to simultaneously rotate the respective cams 8 and 11 so that the adjacent ends 7 as well as the adjacent ends 10 of the brake shoes 3 are expanded to cause the brake shoes to frietionally engage the brake drum liner 5.

By efiecting an expansive movement of the brake shoes at the usual pivot ends as well as at the usual cam ends, the brake shoes evenly engage thev drum throughout their extent, thus producing an even wear of the brake shoe linings.

The provision of the equalizing bar 21 ensures the equal distribution of braking pressure to both of the operating cams 8 and 11.

Having now described our invention, what we claim as new and desire to secure by Letters Patent. is:--

In a. vehicle brake. the combination with a brake drum, brake heads mounted in said drum andhaving opposite pairs of adjacent flee ends, and a cam for 5 reading each pair connected to said equalizing bar at a point of free ends, of a shaft or operating each intermediate the ends of the bar. cam, an operating arm secured to each shaft, In testimony whereof we have hereunto 10 :1- link connected to one arm, an equalizing set our hands.

5 bar connected to the other arm, a, third arm connected to said link and to said equalizing CHRISTOPHER P. CASS.

bar, and a fluid pressure operated member JOHN F. CRAIG. 

